Regulation of dynamo-electric machinery.



C. A. FARSNS l1 E, LAW.

REGULATION OY DYNAMO ELTRG TAGEINEEY.

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G. A. PARSONS iz A. E. LAW.

BEGULAT'IGN o? Umm/1.o ELEGTMG MACHINERY.

APILIGATON FLEI) MAY l5, 1908.

.'zzznted Deia. 13, 1910.

[HM ZVK j' v,and also rotary converters,

for converting from one, two or more phases UNITED sTATEs PATENT oEEIcE.

CHARLES ALaERNoN` PARSONS AND ALEXANDER HENRY LAW, '0E NEWCASTLE-UPON-TYNE, ENGLAND; SAID LAW ASsIGN'oR To sAID PARSONS.

REGULATION 0F DYNAMOTELECTRIC MACHINERY.

Specification of Letters Patent.

Patented Dee. 13, 1910.

Application fnedMay 15, l190e. serial No. 433,126.

To all whom 'it may concern.'

Be it known that we, CHARLES ALe'ERNoN PARSONS and ALEXANDER HENRY Law,subjects of the King of Great Britain and Ireland, residing at Heatonlil/Yorks, NewcastleuponeTyne, in the county of Northumberland, England,have invented certain new and useful Improvements in and Relating to theRegulationof Dynamo-Electric chinery, otl which the following is aspeelfication. g' p' This invention relates to'the regula-tion ofalternators, dynamos andthe like, and has Vfor its objectto improvethe'regulation of voltage of one, two or more phase machines that is,machines to continuous current and to provide means for easy adjustmentof the apparatus "to meet ditl'erent working conditions.

In,` Patent No. 925499' dated 22nd `June,

1909, Charles Algernon Parsons and Alex' ander Henry Law, there isdescribed means' for improving the regulation of alternators and dynamosby the use of a leakage path having a windingthrough which alternat-ving current is passed. It is found, however,

- that in alternators with two or more phses the insertion of a leakagepath winding 1n one phase only causes an inequality of the reasons thisinequal- Iity may prove n objectionable.

The present invention consists in providing separate leakage pathsgoverned byv all or part of the phases and in regulating. the effect ofthe leakage paths by varying the current lpassing' yaround the leakagepaths; for Instance, ina three-phase alternatorv there may be threeleakage-paths, one con-- nected 4to each phase, and also,'in cases wherea wire is led from the star connection ing. n l y,

.Referring to the l get :ompanyingi` diagram v matic drawings, Fgue 1- aView.. Show another leakage pathv'may be provided, in that if desired.

The invention further consists in regulating the effect of the leakagepath by providing a secondary winding .on the leakage path and byvarying the etleet of such leakage path by varying the electricalconstants such as capacity, inductnce orresistanceof the clrcultcontaining such secondary winding diagrammatical yA one -form -of theleakage path applied tothe exciting magnets of an alternator; Fig. 3shows diagram# matically the application of the invention to athree-phase' machine, Fig. 4. being a plan showing the arrangement ofthe leakage paths, andl Fig. 5 an elevation of the same.

In the arrangement illustrated in Figs. 1 and 2 the leakage path Z isinserted between the projections It: 'on the poles p of the excitingmagnets. Alternating current is passed through a lwinding a on theleakage path anda secondary winding b is also provided on the leakagepath, which is cdnveniently made so as to form a closed magneticcircuit. 'The secondary winding b on the leakage path isclosed through acircuit including means such as a capacity c for varying the electricalconstants of the circuit. It Will be seen that if the capacity be variedthe alternating current in the secondary winding will vary, causingzavariation in the magnetic flux which will pass through vthe magneticmaterial of the leakage pat-h Z so that variation of the capacity@ willproduce a variation of the linx passing through the armature 1- of 'theexciter-between the polesfp. v'

In the arrangementv illustrated .in Figs. 3', 4 and 5 three leakage-pat-hs 9, 10, llare provided between proj ections 7c: on the poles' ofthe exciting magnets, and three windings are provided on the three.phase alternator b and wound on the leakage paths respecf,

tively. Three windings are also provided on theleakage pathscorresponding with the 4three capacities 14,15, 16 and forming threecircuits, each of which includes one of the capacities '14, 15, 16,which vmay bev varied by any suitablevmeans such as 'screw devices 24,25, 26 illustrated. Alternating current proportional to the load issupplied to the primary -windings on .the leakage paths from thetransformers 21, 22 and 23.

In the devices illustrated the leakage paths are arranged on one side ofthe: pole pieces. They can, however, be so distributed vthat 'some aresituatedbetween, one pair of pole horns and some between'anotherpairofpole horns, or they are all arranged on both Sides. Their windings canbe' arranged either in series or in parallel with one another, and inthe case of inultipolar roa. chinesare arranged either all in Series orloo fallffi'nfparallel withone another. Somepoles 4 Jalso beA providedwith leakage paths,

some connected to one phase and some to another phase. As a matter offact, the distribution of the leakage paths can be effected in anTdesired manner; but it is preferable so to arrange that the leakagehetween each pair of -poles on the exciter or main magnets isapproximately the same Value, so as to equalize the effect on the lieldas much as possible and to ohtain the same value in each phase. rl`heamount,- ot compounding given hy these leakage paths can be Varied by;varying the number of the leakage paths. For instance, in some cases ita three phase plant be'rnn on non-inductive load only, the windii'igs onone or two leakage paths may he used, while the others are shortcircuited or rendered inoperative. For 'a power factor corresponding toa phase difference of 8() degrees three leakage paths may be employed.

In many cases it is preferable to combine two or more phases in one ormore transformers, and to feed one or more leakage paths from thesetransformers. In a three hase machine for'lexain ale the three )hasecurrent may be eonrertedinto one phase eurrent, the strength of which isdependent on the currents of all three phases, and then this current mayloe used for feeding one or more leakage paths.

Having now described our invent-ion, what we claim as new and desire tosecure by Letters Patent is l. Means for regulating the voltage ofalternating current machines cominfising in combination, field magnetslniring poles, magnetic material connecting said poles, a primar)Ywinding on said mag eiic nniteria'l, a circuit including a siaoi'ldarywinding on said magnetic material, and means lto; vvarying theelectrical constants et said circuit.

Means :tor regulating the Voltage of polyphase alternating currentmachines, comprising in coinhination, field magnets having poles, aplinfalit'y of paths ot inagnetic material connecting said poles,windings en said paths magnetic material, and means for 'supplyingalternating current olf different phases to said windings.

3. Means for regulating the AVoltage of polyphase alternating currentmachines, eon'iprising in coinhiiuition.y lield magnets haring poles, aplurality ot paths el niagnetic materia-l connecting said poles, primarywindings en said paths oit mag material, circuits including secondarywinaings on said paths, means 'for varying the electrical constants ofsaid circuits, and means for supliilying alternating current ofdifferent pha to said primaryv windings.

In testimony whereof, we allix our signatures in presence of twowitnesses.

CHARLES ALGERNN PARSONS. ALEXANDER HENRY LAW.

lVitnesses I HENRY GRAHAM Dainns, WILLIAM MnNzins JOHNSTON.

